pcmhacking.net

VL400 wrote:

Biggvl wrote:How fast do you think the switching between maps would occur?

25ms for the pwr/econ switch polling.
https://pcmhacking.net/forums/viewt ... tch#p76977

40hZ loop speed?

Been thinking a lot about this again as the new engine nears completion, I would really have liked to come up with a computer controlled traction means but it appears that it will need to be driver controlled by means of a map switch mounted on the steering wheel (one map that has much less timing to kill torque than the other), unless anyone has better ideas?
Does anyone know where to get a quality steering wheel mounted switch with a bungee cord?

Motec have switch and cable set up's like that. Probable expensive though. I'll hunt around later see what comes up. There's local re seller's.

We used a coiled headphone extension cord from jaycar wrapped round the boss kit with a push button also from jaycar mounted in one spoke

@delco, is the switch something that's easy to operate with gloves on?

I just had a re-read of the 12p advanced guide and the map switch section, it does say that you need to apply an earth to the pin , but is it a momentary switch of earth that's required or an on/off? Also what's the best method of a visual indicator as to which map you're using, light hooked up to a flex output?

Another option is ALDL logger V2 with custom firmware. Has two digital inputs for front and rear wheel speed sensors, and then have it send mode 4 spark retard values based on slip value.

I have a V2

I have no idea about firmware

Happy to be a test dummy, I'm very capable of fitting sensors to the wheels

I had a chance tonight to drive a couple of Commodores in anger on dirt to see how traction control works in different models, first was a VX Berlina ecotec 6cyl, as Psyolent suggested they fall flat on their face when wheel slip is present with little to no acceleration possible whilst wheel slip or near slip is detected. If I had that in the race car I would get run over
The second was my 6cyl WM caprice, in that I can mash the throttle, power dulls but the car still accelerates, if I stay in it, it gets faster and faster with little to no slip. It is really predictable, linear, responsive and most importantly what I think I'm after for the race car.

Now I have no idea how the two different PCM's are handling this but there is a huge difference. Anybody have any ideas on how to find out?

On the VX ecotec pcm you can tune the traction control settings. On our car I removed the cylinder cut and altered available torque table. Will spin and slide a little but will cut power if excessive. (Still enough to scare the missus )

I believe the system works via the abs system to monitor wheel speeds.

WM is in another league altogether, bit like comparing a calculator with a PC.
WM has electronic throttle so when reduced torque request is received it can just close the throttle.
VX V6vcan only cut cylinders to reduce torque which is very crude. Early LS1s with cable throttle had the throttle relaxer which you could feel on the pedal as it tried to close the throttle.
You can adjust the VX V6 to cut less cylinders to minimise the amount of torque it can reduce which would help, from factory it is a very scary system when there is loose gravel at an intersection.